The present invention relates to a method of allocating board slot numbers, and more particularly to a method of allocating board slot numbers without altering software in a computer control system which is subject to system structure variations.
Generally, a computer control system uses a number of boards and may be subject to a system structure variation dependent on an object to be controlled. When the address map is required to vary by a system structure, the compatibility of software is lost even if the system structure is subordinate, and new software should be formed or software should be converted. However, the development of software requires the expenditure of considerable time and cost, and the conversion of software is not easy to perform.
It is therefore necessary to have the address map unchanged even if the system structure varies. This requires an addressing process for each board when the device is assembled, but such a process is troublesome.
It is customary to input board slot numbers from a back panel connector so that addressing can automatically be effected dependent on a slot position on a back panel. One solution to keep the same address map for all system structures is to use the same back panel for maximum and minimum systems. Each board is mounted on the slot corresponding to its address. However, when the difference between maximum and minimum systems is large, it would be quite wasteful if the same back panel were employed.